Automated additive manufacturing system for printing three-dimensional parts, printing farm thereof, and method of use thereof

ABSTRACT

An additive manufacturing system comprising a platen assembly configured to restrain and release a film, a head gantry configured to retain a print head for printing a three-dimensional part on the restrained film, and a removal assembly configured to draw the film having the printed three-dimensional part from the platen assembly and to cut the drawn film.

BACKGROUND

The present disclosure relates to additive manufacturing systems forprinting or otherwise building three-dimensional (3D) parts withlayer-based, additive manufacturing techniques. In particular, thepresent disclosure relates to additive manufacturing systems forprinting multiple, successive 3D parts in an automated manner.

Additive manufacturing systems are used to print or otherwise build 3Dparts from digital representations of the 3D parts (e.g., AMF and STLformat files) using one or more additive manufacturing techniques.Examples of commercially available additive manufacturing techniquesinclude extrusion-based techniques, jetting, selective laser sintering,powder/binder jetting, electron-beam melting, and stereolithographicprocesses. For each of these techniques, the digital representation ofthe 3D part is initially sliced into multiple horizontal layers. Foreach sliced layer, a tool path is then generated, which providesinstructions for the particular additive manufacturing system to printthe given layer.

For example, in an extrusion-based additive manufacturing system, a 3Dpart may be printed from a digital representation of the 3D part in alayer-by-layer manner by extruding a flowable part material. The partmaterial is extruded through an extrusion tip carried by a print head ofthe system, and is deposited as a sequence of roads on a substrate in anx-y plane. The extruded part material fuses to previously deposited partmaterial, and solidifies upon a drop in temperature. The position of theprint head relative to the substrate is then incremented along a z-axis(perpendicular to the x-y plane), and the process is then repeated toform a 3D part resembling the digital representation.

In fabricating 3D parts by depositing layers of a part material,supporting layers or structures are typically built underneathoverhanging portions or in cavities of 3D parts under construction,which are not supported by the part material itself. A support structuremay be built utilizing the same deposition techniques by which the partmaterial is deposited. The host computer generates additional geometryacting as a support structure for the overhanging or free-space segmentsof the 3D part being formed. Support material is then deposited from asecond nozzle pursuant to the generated geometry during the printingprocess. The support material adheres to the part material duringfabrication, and is removable from the completed 3D part when theprinting process is complete.

SUMMARY

An aspect of the present disclosure is directed to an additivemanufacturing system that includes a platen gantry, a platen assembly,and head gantry, and a removal assembly, and preferably prints andremoves 3D parts (and any associated support structures) in an automatedmanner. The platen assembly includes a platform portion configured to beoperably retained by the platen gantry, and having a surface. The platenassembly also includes a retention bracket biased towards the platformportion and configured to engage the surface of the platform portion forrestraining a film therebetween, and to disengage from the surface torelease the film. The head gantry is configured to retain a print headfor printing a 3D part on the restrained film. The removal unit isconfigured to draw the film having the printed 3D part from the platenassembly and, optionally, to cut the drawn film.

Another aspect of the present disclosure is directed to an additivemanufacturing system that includes a platen assembly configured torestrain and release a film, and a head gantry configured to retain aprint head for printing 3D parts onto the restrained film. The systemalso includes a removal assembly configured to draw the released filmhaving the printed three-dimensional parts, and a mechanism forretaining a supply of the film, wherein the mechanism is not retained bythe platen assembly.

Another aspect of the present disclosure is directed to a method forprinting a three-dimensional part with an additive manufacturing system.The method includes restraining a segment of a film against a surface ofa platen assembly, printing the 3D part on the restrained film segment,releasing the film segment having the printed 3D part, drawing thereleased film segment having the printed 3D part from the platenassembly to a removal assembly, and cutting the drawn film segmenthaving the printed 3D part to separate the film segment from asubsequent segment of the film.

DEFINITIONS

Unless otherwise specified, the following terms as used herein have themeanings provided below:

The terms “preferred” and “preferably” refer to embodiments of theinvention that may afford certain benefits, under certain circumstances.However, other embodiments may also be preferred, under the same orother circumstances. Furthermore, the recitation of one or morepreferred embodiments does not imply that other embodiments are notuseful, and is not intended to exclude other embodiments from the scopeof the present disclosure.

Directional orientations such as “above”, “below”, “top”, “bottom”, andthe like are made with reference to a layer-printing direction of a 3Dpart. In the embodiments shown below, the layer-printing direction isthe upward direction along the vertical z-axis. In these embodiments,the terms “above”, “below”, “top”, “bottom”, and the like are based onthe vertical z-axis. However, in embodiments in which the layers of 3Dparts are printed along a different axis, such as along a horizontalx-axis or y-axis, the terms “above”, “below”, “top”, “bottom”, and thelike are relative to the given axis.

The term “providing”, such as for “providing a print head”, when recitedin the claims, is not intended to require any particular delivery orreceipt of the provided item. Rather, the term “providing” is merelyused to recite items that will be referred to in subsequent elements ofthe claim(s), for purposes of clarity and ease of readability.

The terms “printing onto”, “printing on” such as for “printing a 3D parton a film” include direct and indirect printings onto the film. A“direct printing” involves depositing a flowable material directly ontothe film to form a layer that adheres to the film. In comparison, an“indirect printing” involves depositing a flowable material ontointermediate layers that are directly printed onto the film. As such,unless otherwise specified, printing a 3D part onto a film may include(i) a situation in which the 3D part is directly printed onto to thefilm, (ii) a situation in which the 3D part is directly printed ontointermediate layer(s) (e.g., of a support structure), where theintermediate layer(s) are directly printed onto the film, and (iii) acombination of situations (i) and (ii).

The terms “about” and “substantially” are used herein with respect tomeasurable values and ranges due to expected variations known to thoseskilled in the art (e.g., limitations and variabilities inmeasurements).

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic illustration of a printing farm that includes aplurality of automated additive manufacturing system of the presentdisclosure.

FIG. 2 is a top, front perspective view of an automated additivemanufacturing system of the present disclosure in use with consumableassemblies.

FIG. 3 is a top, right isometric view of a platform assembly of thesystem in use with a film.

FIG. 4 is an exploded isometric view of the platform assembly.

FIG. 5 is a top, right isometric view of the platform assembly and aremoval assembly of the system in use with a film.

FIG. 6 is a top, right isometric view of the removal assembly.

FIG. 7 is a top, right isometric view of subcomponents of the removalassembly.

FIG. 8 is a top, left isometric view of the subcomponents of the removalassembly.

FIG. 9 is an expanded perspective view of subcomponents of a cuttingunit of the removal assembly.

FIG. 10 is a front view of the subcomponents of the cutting unit.

FIG. 11 is a top, right isometric view of a door assembly of the system.

FIG. 12 is a bottom, left isometric view of the door assembly.

FIG. 13 is an expanded view of a drive mechanism of the door assembly.

FIGS. 14A-14G are schematic illustrations of the system, depicting aprocess for printing and removing a 3D part and support structure.

FIG. 15 is an exploded isometric view of a first alternative platformassembly having a substrate with surface holes and a porous interlayerregion.

FIG. 16 is a side view of the substrate shown in FIG. 15 with a printedsupport structure.

FIG. 17 is an exploded isometric view of a second alternative platformassembly having a substrate with surface holes and a non-porousinterlayer region.

FIG. 18 is a side view of the substrate shown in FIG. 17 with a printedsupport structure.

FIG. 19 is an exploded isometric view of a third alternative platformassembly having a substrate with surface holes, a porous interlayerregion, and hook slots.

FIG. 20 is a side view of the substrate shown in FIG. 19 with a printedsupport structure.

FIG. 21 is an exploded isometric view of a fourth alternative platformassembly having a substrate with surface holes, a non-porous interlayerregion, and hook slots.

DETAILED DESCRIPTION

The present disclosure is directed to an additive manufacturing systemfor printing and removing 3D parts and support structures in anautomated manner. In a conventional additive manufacturing system, auser is typically required to manually remove a printed 3D part from thesystem after the printing operation is completed. As can be appreciated,this can increase time and labor to print 3D parts, and requires usersto physically remove the 3D parts prior to starting subsequent printingoperations. In comparison, the additive manufacturing system of thepresent disclosure is capable of printing multiple successive 3D parts,where the system is also configured to remove the 3D parts withoutrequiring user intervention.

The additive manufacturing system of the present disclosure may also beincorporated into a printing farm, such as printing farm 10 fillustrated in FIG. 1. As shown, printing farm 10 f includes multipleadditive manufacturing systems 10, where at least a portion of thesystems 10, and more preferably each system 10, prints and removes 3Dparts in an automated manner without requiring user intervention. Aftereach 3D part is printed and removed from one of the systems 10, such aswith one or more receiving devices 11 (e.g., receptacles, conveyormechanisms, etc. . . . ), the support structure associated with the 3dpart may be removed (if necessary), and the 3D part may optionallyundergo one or more post-processing steps (e.g., vapor smoothing).Accordingly, printing farm 10 f is suitable for use with automatedsupport removal systems (e.g., as disclosed in Swanson et al., U.S.Publication No. 2013/0075975 and automated post-processing systems(e.g., as disclosed in Zinniel, U.S. Pat. No. 8,075,300).

As discussed below, each system 10 may include a platform assembly and aremoval assembly, which may draw successive segments of a film from aspool supply (or other supply source). Briefly, the platform assemblyand the removal assembly may engage each other to draw the film across atop surface of the platform assembly, where the film is then preferablyrestrained against the top surface. The system 10 may then print a 3Dpart (or multiple 3D parts) and, optionally, one or more supportstructures on the restrained film.

After the printing operation is completed, the platform assembly mayrelease the film, and the removal assembly may then draw the film fromthe platform assembly and cut the film to separate the segment retainingprinted 3D part from the remainder of the film. The cut segment with theprinted 3D part may then exit the system and be received by receivingdevice(s) 11 (e.g., dropped out of the system into a bin, otherreceptacle, or a conveyor mechanism). In some embodiments, such as thosein which the system 10 includes a heated chamber, the system 10 may alsoinclude an automated door. In these embodiments, the given system 10 mayalso open the automated door, allowing the cut film segment with theprinted 3D part to exit from the system 10.

After the printed 3D part exits the system 10, the same system 10 maythen begin printing a subsequent 3D part following the same steps. Ascan be appreciated, the use of printing farm 10 f, with each system 10operating in an automated manner, can substantially increase throughputof the printing operations without sacrificing part quality. This canaccordingly reduce manufacturing times and costs, and increasingoperational efficiencies.

FIG. 2 shows an example system 10 in use with two consumable assemblies12, where system 10 is configured to print and remove 3D parts andsupport structures in an automated manner, preferably without userintervention. Each consumable assembly 12 is an easily loadable,removable, and replaceable container device that retains a supply of aconsumable filament for printing with system 10. Typically, one of theconsumable assemblies 12 contains a part material filament (“partmaterial consumable assembly”), and the other consumable assembly 12contains a support material filament (“support material consumableassembly”). However, both consumable assemblies 12 may be identical instructure.

In the shown embodiment, each consumable assembly 12 includes containerportion 14, guide tube 16, print head 18, and handle 20. Containerportion 14 may retain a spool or coil of a consumable filament, such asdiscussed in Mannella et al., U.S. Publication Nos. 2013/0161442 and2013/0161432. In some embodiments, container portions 14 of consumableassemblies 12 may retain large supplies (e.g., 900 cubic inches) of theconsumable filaments. This is particularly suitable for use in aprinting farm of automated systems 10 to increase the duration betweenchange-overs of each consumable assembly 12.

Guide tube 16 interconnects container portion 14 and print head 18,where the drive mechanism of print head 18 draws successive segments ofthe consumable filament from container portion 14 and through guide tube16. In this embodiment, guide tube 16 and print head 18 aresubcomponents of consumable assembly 12, and may be interchanged to andfrom system 10 with each consumable assembly 12. In alternativeembodiments, guide tube 16 and/or print head 18 may be components ofsystem 10, rather than subcomponents of consumable assemblies 12.

System 10 is an additive manufacturing system for printing 3D parts ormodels and corresponding support structures (e.g., 3D part 22 andsupport structure 24) from the part and support material filaments,respectively, of consumable assemblies 12, using a layer-based, additivemanufacturing technique; and for removing the printed 3D parts andsupport structures in an automated manner. Suitable additivemanufacturing systems for system 10 include extrusion-based systemsdeveloped by Stratasys, Inc., Eden Prairie, Minn. under the trademarks“FDM” and “FUSED DEPOSITION MODELING”. As shown, system 10 includessystem casing 26, two bays 28, chamber 30, platen assembly 32, removalassembly 34, door assembly 36, head carriage 38, head gantry 40, z-axismotor 42, and a pair of x-y motors 44.

System casing 26 is a structural component of system 10 and may includemultiple structural sub-components such as support frames, housingwalls, and the like. In the shown embodiment, system casing 26 definesthe dimensions of bays 28, and of chamber 30. Bays 28 are container baysconfigured to respectively receive container portions 14 of consumableassemblies 12. Typically, each of bays 28 may be intended to receiveeither a part material consumable assembly 12 or a support materialconsumable assembly 12. In an alternative embodiment, bays 28 may beomitted to reduce the overall footprint of system 10. In thisembodiment, container portions 14 may stand adjacent to system casing26, while providing sufficient ranges of movement for guide tubes 16 andprint heads 18. Bays 28, however, provide convenient locations forloading consumable assemblies 12.

Chamber 30 is an enclosable environment that contains platen assembly 32and removal assembly 34 for printing 3D part 22 and support structure24, as discussed below. Chamber 30 may be heated (e.g., with circulatingheated air) to reduce the rate at which the part and support materialssolidify after being extruded and deposited (e.g., to reduce distortionsand curling), or otherwise maintained to provide a controlledenvironment. In alternative embodiments, chamber 30 may be omittedand/or replaced with different types of build environments. For example,3D part 22 and support structure 24 may be built in a build environmentthat is open to ambient conditions or may be enclosed with alternativestructures (e.g., flexible curtains).

In the shown embodiment, chamber 30 is accessible through door assembly36, which, in the shown embodiment, includes bi-fold door 46 (shown inan open state). Door assembly 36 allows the printed 3D part 22 andsupport structure 24 to be removed from system 10 in an automated mannervia platen assembly 32 and removal assembly 34, as discussed below.While illustrated with bi-fold door 46, door assembly 36 mayalternatively include different automated door designs, such asaccordion-based doors, hinged doors, and the like.

Platen assembly 32 is supported by a platen gantry of system 10 (notshown in FIG. 2), where the platen gantry is configured to move platenassembly 32 along (or substantially along) the vertical z-axis and ispowered by z-axis motor 42. Platen assembly 32 is configured to receiveand restrain film 48. Film 48 is preferably a flexible film thatfunctions as a receiving surface for printing 3D part 22 and supportstructure 24, and is drawn from a spool supply 50 that may be locatedoutside of chamber 30 and/or system 10. Film 48 preferably exhibits goodbond strengths to support structure 24, allowing support structure 24 toanchor 3D part 22 to reduce the effects of curling. For example, film 48may be fabricated from one or more materials, such as polycarbonate,acrylic/alkyl acrylic, paper-based, polyester, cellulose, polyamideand/or polyolefin materials, and may be a multi-layer film.

In comparison to platen assembly 32, in the shown embodiment, removalassembly 34 is secured to the front end of chamber 30, adjacent to doorassembly 36. As such, the movement of platen assembly 32 along thevertical z-axis engages and disengages platen assembly 32 to and fromremoval assembly 34, as discussed below. In an alternative embodiment,removal assembly 34 may be secured to the front end of platen assembly32, allowing removal assembly 34 to move along the vertical z-axis withplaten assembly 32. However, removal assembly 34 and spool supply 50 arepreferably separate from platen assembly 32, thereby reducing the weightof platen assembly 32, and fixed relative to chamber 30.

Head carriage 38 is a unit configured to receive one or more removableprint heads, such as print heads 18, and is supported by head gantry 40.Examples of suitable devices for head carriage 38, and techniques forretaining print heads 18 in head carriage 38, include those disclosed inSwanson et al., U.S. Publication Nos. 2010/0283172 and 2012/0164256.

As mentioned above, in some embodiments, guide tube 16 and/or print head18 may be components of system 10, rather than subcomponents ofconsumable assemblies 12. In these embodiments, additional examples ofsuitable devices for print heads 18, and the connections between printheads 18 and head gantry 40 include those disclosed in Crump et al.,U.S. Pat. No. 5,503,785; Swanson et al., U.S. Pat. No. 6,004,124;LaBossiere, et al., U.S. Pat. Nos. 7,384,255 and 7,604,470; Batchelderet al., U.S. Pat. No. 7,896,209; and Comb et al., U.S. Pat. No.8,153,182. Moreover, in alternative embodiments, print heads 18 mayutilize different deposition-based additive manufacturing techniques.For example, print heads 18 may be inkjet-based print heads, each havingone or more arrays of inkjet orifices to print 3D part 22 and supportstructure 24.

In the shown embodiment, head gantry 40 is a belt-driven gantry assemblyconfigured to move head carriage 38 (and the retained print heads 18) in(or substantially in) a horizontal x-y plane above chamber 30, and ispowered by x-y motors 44. Examples of suitable gantry assemblies forhead gantry 40 include those disclosed in Comb et al., U.S. patent Ser.No. 13/242,561.

In an alternative embodiment, platen assembly 32 may be configured tomove in the horizontal x-y plane within chamber 30, and head carriage 38(and print heads 18) may be configured to move along the z-axis. Othersimilar arrangements may also be used such that one or both of platenassembly 32 and print heads 18 are moveable relative to each other.Platen assembly 32 and head carriage 38 (and print heads 18) may also beoriented along different axes. For example, platen assembly 32 may beoriented vertically and print heads 18 may print 3D part 22 and supportstructure 24 along the x-axis or the y-axis.

As further shown in FIG. 1, system 10 may also include a pair of sensorassemblies 52, which, in the shown embodiment, are located adjacent tobays 28. Sensor assemblies 52 are configured to receive and retain guidetubes 16, while also providing sufficient ranges of movement for guidetubes 16 and print heads 18. Sensor assemblies 52 are also configured toread encoded markings from successive segments of the consumablefilaments moving through guide tubes 16. Examples of suitable devicesfor sensor assemblies 52 include those disclosed in Batchelder et al.,U.S. Patent Application Publication Nos. 2011/0117268, 2011/0121476, and2011/0233804.

System 10 also includes controller 54, which is one or more controlcircuits configured to monitor and operate the components of system 10.For example, one or more of the control functions performed bycontroller 54 can be implemented in hardware, software, firmware, andthe like, or a combination thereof. Controller 54 may communicate overcommunication line 56 with print heads 18, chamber 30 (e.g., with aheating unit for chamber 30), removal assembly 34, door assembly 36,head carriage 38, motors 42 and 44, sensor assemblies 54, and varioussensors, calibration devices, display devices, and/or user inputdevices. In some embodiments, controller 54 may also communicate withone or more of bays 28, platen assembly 32, head gantry 40, and anyother suitable component of system 10. In further embodiments,controller 54 may also direct the operation of platen assembly 32,removal assembly 34 and/or door assembly 36 based on informationreceived from other components of system 10, such as from sensorassemblies 54.

While illustrated as a single signal line, communication line 56 mayinclude one or more electrical, optical, and/or wireless signal lines,allowing controller 54 to communicate with various components of system10. Furthermore, while illustrated outside of system 10, controller 54and communication line 56 may be internal components to system 10.System 10 and/or controller 54 may also communicate with one or morecomputer-based systems (not shown), which may include computer-basedhardware, such as data storage devices, processors, memory modules andthe like for generating, storing, and transmitting tool path and relatedprinting instructions to system 10.

System 10 is also shown in use with bucket 58 retained by casing 26adjacent to door assembly 36. Bucket 58 is a receptacle configured toreceive the printed 3D part 22 and support structure 24 when removedfrom system 10. As discussed below, after 3D part 22 and supportstructure 24 are printed, removal system 34 preferably draws film 48until the segment of film 48 retaining the printed 3D part 22 andsupport structure 24 passes removal assembly 34 and extends through theopening of door assembly 36. Removal system 34 then cuts film 48,allowing the printed 3D part 22 and support structure 24 to fall intobucket 58. In some embodiments, bucket 58 may be lined with one or morecushioning materials to reduce any impact that 3D part 22 and supportstructure 24 may be subjected to when removed from system 10.

In alternative embodiments, bucket 58 may be replaced by other suitabledevices for receiving the removed 3D part 22 and support structure 24.For example, bucket 58 may be replaced with a support removal system(not shown), which may optionally communicate with controller 54 and/orthe host computer. In this embodiment, 3D part 22 and support structure24 may drop out of chamber 30 and into the support removal system toremove support structure 24 from 3D part 22, also preferably in anautomated manner. Examples of suitable support removal systems includethose disclosed in Swanson et al., U.S. Publication No. 2013/0075975;and Dunn et al., U.S. Publication No. 2011/0186081.

In a further alternative embodiment, bucket 58 may be replaced with aconveyor mechanism, where the removed 3D part 22 and support structure24 may drop onto a conveyor belt, which transports the received 3D part22 and support structure 24 to a desired location away from system 10.This is suitable for use with a printing farm of systems 10, such asprinting farm 10 f shown in FIG. 1, where a network of conveyor beltsmay transport the 3D parts and support structures from the individualsystems 10 to one or more locations for further processing (e.g.,support removal).

FIGS. 3-10 illustrate example embodiments for platen assembly 32 andremoval assembly 34. As shown in FIGS. 3 and 4, platen assembly 32includes vacuum platen 60, retention bracket 62, and wheel units 64,each of which may be fabricated from one or more metallic and/orthermally-stable polymeric materials. Vacuum platen 60 includes platformportion 66 (having top surface 68 located below film 48), arm extensions70, and a pair of bias tabs 72. Top surface 68 includes indentations 74and vacuum hole 75 (shown in FIG. 4) for drawing a vacuum across topsurface 68. The drawn vacuum holds film 48 down against top surface 68during printing operations, preventing film 48 from shifting while 3Dpart 22 and support structure 24 are printed. Restraining film 48 inthis manner allows support structure 24 to effectively anchor the layersof 3D part 22, thereby reducing curling effects on 3D part 22.

Arm extensions 70 extend from the rear side of platform portion 66, andprotrude through slits in a rear wall of chamber 30 (e.g., rear wall176, shown below in FIGS. 14A-14G) to engage the platen gantry (e.g.,platen gantry 174, shown below in FIGS. 14A-14G) of system 10 outside ofchamber 30. This engagement allows the platen gantry to move platenassembly 32 along the vertical z-axis within chamber 30. Wheel units 64each include mounting blocks 64 a and idler wheels 64 b rotatablysecured to mounting blocks 64 a, where idler wheels 64 b may includerubber-coated surfaces, if desired. Mounting blocks 64 a are accordinglymounted to the front end of platform portion 66 at top surface 68.

Retention bracket 62 is a U-shaped bracket that covers the periphery oftop surface 68, thereby exposing film 48 at top surface 68. Retentionbracket 62 includes a pair of bias tabs 76, lateral edges 78, andcalibration target 80. Bias tabs 72 and 76 align are aligned and retainsprings 81 a and bolts 81 b or other biasing mechanisms that compress orotherwise bias lateral edges 78 of retention bracket 62 downward againsttop surface 68. This also assists in restraining film 48, in addition tothe drawn vacuum, where the edges of film 48 are pressed between topsurface 68 and lateral edges 78. Calibration target 80 is one or moremarkings suitable for calibrating print heads 18, such as disclosed inLeavitt et al., U.S. Publication No. 2013/0242317.

As shown in FIG. 5, during a printing operation, print heads 18 mayprint 3D part 22 and support structure 24 in a layer-by-layer manneronto the segment of film 48 restrained against top surface 68. When theprinting operation is completed, platen assembly 32 may be lowered downalong the vertical z-axis to engage removal assembly 34, as illustratedby arrows 82.

Retention bracket 62 may then disengage from platform portion 66 and thedrawn vacuum may be halted. This releases film 48 from top surface 68.Removal assembly 34 may then draw film 48 (and the printed 3D part 22and support structure 24) in the direction of arrows 84 until thesegment of film 48 that retains the printed 3D part 22 and supportstructure 24 moves past the front end of removal assembly 34. Asdiscussed further below, removal assembly 34 may then cut film 48,allowing the printed 3D part 22 and support structure 24 to drop out ofchamber 30 and into bucket 58 (or other suitable receptacle or conveyormechanism).

As shown in FIGS. 5 and 6, removal assembly 34 includes circuit board85, frame portion 86, film drive mechanism 88, and cutting mechanism 90,where frame portion 86, film drive mechanism 88, and cutting mechanism90 may each be fabricated from one or more metallic and/orthermally-stable polymeric materials. Circuit board 85 is one or moreelectronic circuits supported by frame portion 86 and preferablycommunicates with controller 54 (via communication line 56) to operatefilm drive mechanism 88 and cutting mechanism 90.

Frame portion 86 includes top surface 92 and lateral flanges 94, wheretop surface 92 includes roller port 96. Top surface 92 preferably alignsin the x-y plane with top surface 68 of platform portion 66 whenplatform assembly 32 engages removal assembly 34.

FIGS. 7 and 8 further illustrate film drive mechanism 88 and cuttingmechanism 90 with frame portion 84 and circuit board 85 omitted, whereFIG. 7 is the same isometric view as shown in FIG. 6, and FIG. 8 is theopposing isometric view from that shown in FIGS. 6 and 7. As shown, filmdrive mechanism 88 includes motor 98, drive gears 100 and 102, driveshaft 104, and drive roller 106. Motor 98 is an electric motorconfigured provide rotational power to drive gear 100, where drive gear100 is axially connected to motor 98 and is supported by one of flanges94 (shown in FIG. 6).

Drive gear 102 is rotatably engaged with drive gear 100 and axiallyconnected to drive shaft 104, where the ends of drive shaft 104 aresupported by flanges 94. This arrangement allows the rotational power ofmotor 98 to rotate drive shaft 104 and drive roller 106, where driveroller 106 is axially connected to drive shaft 104, and extends throughport 96 of top surface 90 (as shown in FIGS. 5 and 6). Drive roller 106may also include surface features, such as a knurled surface.

When platen assembly 32 lowers down and engages removal assembly 34, theleading end of film 48 is nipped between the left-side idler wheel 64 band drive roller 106. This allows the rotation of drive roller 106 todraw film 48 (and the printed 3D part 22 and support structure 24) inthe direction of arrow 84. The right-side idler wheel 64 b may nip film48 against top surface 92 to keep film 48 aligned while being drawn. Inan alternative embodiment, film drive mechanism 88 may include a seconddrive roller 106 (not shown) aligned with the right-side idler wheel 64b, and extending through a second port 96 (not shown) in top surface 92,to assist in driving film 48 in the direction of arrow 84.

Additionally, drive shaft 104 may include encoder magnet 107, which isreadable by a reciprocating encoder reader on circuit board 85 (shown inFIG. 6) to allow controller 54 to monitor the rotation of drive wheel106, and hence, the rate and distance that film 48 is drawn. As such,controller 54 may direct motor 98 to operate to draw film 48 in thedirection of arrow 84 for a predefined length (based on the number ofrotations of drive shaft 104), which preferably corresponds to thedistance at which 3D part 22 and support structure 24 move sufficientlypast top surface 92 of removal assembly 34.

Cutting mechanism 90 extends generally parallel to film drive mechanism88, and includes motor 108, drive gears 110 and 112, power ortranslation screw 114, linear bearing 116, and blade unit 118. Motor 108is a second electric motor configured provide rotational power to drivegear 110, where drive gear 110 is axially connected to motor 108 and issupported by one of flanges 94 (shown in FIG. 6). Drive gear 112 isrotatably engaged with drive gear 110 and axially connected to powerscrew 114, where the ends of power screw 114 and linear bearing 116 arealso supported by flanges 94.

Blade unit 118 is threadedly engaged with power screw 114 and slidablyengaged with linear bearing 116, which allows blade unit 118 to movealong the x-axis based on the rotational power of motor 108. Forexample, blade unit 118 may be pulled along the x-axis in the directionof arrow 120 when motor 114 rotates power screw 114 in a firstrotational direction (i.e., to cut film 48), and may be retracted alongthe x-axis in the direction of arrow 122 when motor 108 rotates powerscrew 114 in a second and opposing rotational direction.

Additionally, power screw 114 may include encoder magnet 124 (shown inFIG. 8), which is readable by a second reciprocating encoder reader oncircuit board 85 (shown in FIG. 6) to allow controller 54 to monitor therotation of power screw 114. This allows controller 54 to direct themovement of blade unit 118 in the directions of arrows 120 and 122.

Blade unit 118 includes slide block 126, blade shield 128, backingroller 130, and rotary blade 132 (shown in FIG. 8). Slide block 126 isthe portion of blade unit 118 that is engaged with threaded screw 114and linear bearing 116 for moving blade unit 118 along the x-axis in thedirections of arrows 120 and 122. Shield guard 128 is a bracket that issecured to slide block 126 (e.g., with bolts 133 or other fasters),rotatably supports backing roller 130 and rotary blade 132, andfunctions as a safety shield to prevent users from coming into contactwith rotary blade 132.

FIGS. 9 and 10 further illustrate the engagements between shield guard128, backing roller 130, and rotary blade 132. As shown, shield guard128 includes upper section 134, step-over section 136, and lower section138, where step-over section 136 interconnects upper section 134 andlower section 136. Backing roller 130 is rotatably mounted to uppersection 134 to freely rotate, and extends adjacent to step-over section136 to engage rotary blade 132. In particular, backing roller 130includes annular groove 140, which is configured to receive a peripheraledge 142 of rotary blade 132. backing roller 130 may be fabricated fromone or more metallic, thermoplastic, and/or hard rubber materials.

Rotary blade 132 is rotatably mounted to lower section 138 to freelyrotate, where lower section 138 includes ramp 144 (shown in FIG. 10) tolift film 48 during a cutting operation. For example, film 48 may be cutby pulling blade unit 118 in the direction of arrow 120, as discussedabove. This causes film 48 to engage peripheral edge 142 of rotary blade132 and annular groove 140 of backing roller 130 between upper section134 and lower section 138, where upper section 134 includes a leadingedge 134 a for properly positioning film 48. Film 48 is also lifted atramp 144 to increase the ease of cutting.

The continued movement of blade unit 118 in the direction of arrow 120rotates rotary blade 132 and backing roller 130 against film 48, therebycutting film 48 along the front end of removal assembly 34. As discussedabove, the cut segment of film 48 retaining 3D part 22 and supportstructure 24 may then drop out of chamber 30 through door assembly 36,and into bucket 58 (or other suitable receptacle or conveyor mechanism).

FIGS. 11-13 illustrate a suitable embodiment for door assembly 36. Asshown in FIG. 11, in addition to bi-fold door 46, door assembly 36 alsoincludes base cover 146 having opening 148 for retaining a bucketbracket (for supporting bucket 58 as shown in FIG. 1). In the shownembodiment, bi-fold door 46 includes upper panel 150 and lower panel152, which are hingedly connected together at hinged joints 153. Upperpanel 150 is also hingedly connected to casing 26 at the inlet ofchamber 30 with hinged joints 154.

As shown in FIGS. 12 and 13, door assembly 36 also includes motor 156,miter gears 158, power or translational screw 160, bracket 162 (shown inFIG. 13), threaded nut 164, roller or slider 166 (shown in FIG. 13), andcircuit board 168, where threaded nut 164 and roller 166 are secured toopposing bottom corners of lower panel 152. Motor 156 is an electricmotor secured to base cover 146 and configured to rotate miter gears158. Miter gears 158 accordingly inter-engage motor 156 and power screw160 for rotating power screw 160. The ends of power screw 160 aresupported by casing 26 and bracket 162, where bracket 162 is accordinglysecured to casing 26.

Threaded nut 164 is threadedly engaged with power screw 160, whichallows threaded nut 164 to move along the z-axis based on the rotationalpower of motor 156, which accordingly pulls lower panel 152 of bi-folddoor 46 along the z-axis to open and close bi-fold door 46. For example,threaded nut 164 may be pulled along the z-axis in the direction ofarrow 169 when motor 156 rotates power screw 160 in a first rotationaldirection. This accordingly raises lower panel 152 and upper panel 150around hinged joints 153 and 154, as illustrated by arrows 170, to openbi-fold door 46 to an open state as shown above in FIG. 1. Roller 166correspondingly rolls along a reciprocating tack in casing 26 tomaintain even lifting pressures laterally across lower panel 152.Bi-fold door 46 may also be closed by having motor 156 rotate powerscrew 160 in a second and opposing rotational direction, which pullsthreaded nut 164 and lower panel 152 downward along the z-axis (oppositedirections from arrows 169 and 170).

Power screw 160 may include encoder magnet 172 (shown in FIG. 12), whichis readable by a reciprocating encoder reader on circuit board 168 toallow controller 54 to monitor the rotation of power screw 160. Thisallows controller 54 to direct the opening and closing of bi-fold door46 in an automated manner.

The above-discussed embodiments of removal assembly 34 and door assembly36 are depicted with their electronic components (e.g., circuit boards85 and 168, and motors 98, 108, and 156 being located inside of chamber30. In some embodiments, these components are preferably located outsideof chamber 30, and respectively engage film drive mechanism 88, cuttingmechanism 90, and bi-fold door 46 through the walls of chamber 30. Theseembodiments are particularly suitable when chamber 30 is heated, asdiscussed above, to protect these components from the elevatedtemperatures within chamber 30.

FIGS. 14A-14G depict a process for operating system 10 to print andremove 3D part 22 and support structure 24 in an automated manner. Asshown in FIG. 14A, system 10 also includes platen gantry 174 locatedbehind a rear wall 176 of chamber 30, and which is operably engaged withz-axis motor 42 (shown in FIG. 1).

System 10 further includes film inlet port 178 and hard stop 180. Filminlet port 178 is an opening into the floor of chamber 30 through whichfilm 48 travels between spool supply 50 and platen assembly 32. Spoolsupply 50 is freely suspended below system 10 on support shaft 182,which allows film 48 to freely unwind from spool supply 50. Accordingly,in this embodiment, system 10 may also include a lower frame (not shown)for mounting system 10 above spool supply 50. In alternativeembodiments, spool supply 50 may be located within casing 26. In theseembodiments, film inlet port 178 may be located at other locationsoutside of chamber 30. Moreover, in some embodiments, spool supply 50may be retained entirely within chamber 30, where film inlet port 178may be omitted. However, spool supply 50 is preferably not retained byplaten assembly 32 or platen gantry 174, and also preferably locatedoutside of chamber 30 for ease of access.

Film 48 may be loaded to platen assembly 32 by lowering platen assembly32 until retention bracket 62 contacts hard stop 180. As discussedabove, vacuum platen 60 of platen assembly 32 and retention bracket 62are preferably biased together. However, upon contacting hard stop 180,retention bracket 62 is pressed upward against the bias by the continueddownward movement of vacuum platen 60. For example, controller 54 maydirect platen gantry 174 to lower vacuum platen 60 to a suitable heightwithin chamber 30 to separate retention bracket 62 from top surface 68by a given distance (e.g., by about 0.25 inches).

A leading end of film 48 may then be inserted through film inlet port178 and into the space between the disengaged retention bracket 62 andtop surface 68 of platform portion 66 (of vacuum platen 60). In theshown embodiment, system 10 also includes vacuum pump 184 and vacuumline 186, where vacuum line 186 is connected to platform portion 66 atvacuum hole 75 (shown in FIG. 4) and to vacuum pump 184 for drawing avacuum at top surface 68. Accordingly, after film 48 is inserted betweenretention bracket 62 and top surface 68, controller 54 may direct vacuumpump 184 to draw a vacuum at top surface 68, which holds film 48 downagainst top surface 68.

Controller 54 may then direct platen gantry 174 to raise platen assembly32 along the z-axis to a predetermined height within chamber 30, asillustrated by arrow 188. This disengages retention bracket 62 from hardstop 180, allowing lateral edges 78 of retention bracket 62 to pressback down against film 48 and top surface 68, thereby furtherrestraining film 48 to top surface 68 (along with the drawn vacuum).Because spool supply 50 freely rotates around support shaft 182, theupward movement of platen assembly 32 unwinds film 48 until platenassembly 32 reaches the desired location at the top of chamber 30.

As shown in FIG. 14B, when platen gantry 32 reaches a desired height inchamber 30, controller 54 may then direct motors 44 and head gantry 40to move head carriage 38 (and the retained print heads 18) around in thehorizontal x-y plane above chamber 30. Controller 54 may also directprint heads 18 to selectively draw successive segments of the consumablefilaments from container portions 14 and through guide tubes 16,respectively. Each print head 18 thermally melts the successive segmentsof the received consumable filament such that the filament becomes amolten material. The molten material is then extruded and deposited ontothe segment of film 48 retained by platen assembly 32 to print a layerof 3D part 22 and/or support structure 24.

After each layer is printed, platen gantry 174 may lower platen assembly32 by a single layer increment, as illustrated by arrow 190. As shown inFIG. 14C, as platen assembly 32 continues to incrementally lower, theremaining unwound segment of film 48 may become slack and function as aservice loop. In an alternative embodiment, if desired, spool supply 50may be retained on support shaft 182 in a biased manner that maintains amild level of tension on film 48 to prevent the formation of any serviceloops.

As shown in FIG. 14D, after the print operation is complete, controller54 may direct platen gantry 174 to lower platen assembly 32 back down toremove 3D part 22 and support structure 24. In particular, platenassembly 32 may be lowered down to contact hard stop 180 again, therebydisengaging and lifting retention bracket 62 from top surface 68.Controller 54 may also direct vacuum pump to stop drawing a vacuum,which releases film 48 from top surface 68. Furthermore, controller 54may direct motor 156 of door assembly 36 to open bi-fold door 46, asdiscussed above. If desired, controller 54 may also shut off any blowerin chamber 30 to halt the circulation of heated air while bi-fold door46 is opened.

When platen assembly 32 is in its lowered state and engaged with removalassembly 34, the leading end of film 48 is nipped between the left-sideidler wheel 64 b and drive roller 106, as discussed above. Controller 54may then direct motor 98 to rotate drive roller 106 to draw film 48 (andthe printed 3D part 22 and support structure 24) in the direction ofarrow 84. In the shown example, this also draws film 48 from the slackservice loop up to top surface 68 of platform assembly 32 to function asa receiving surface for a subsequent printing operation.

As shown in FIG. 14E, after a predetermined length of film 48 is drawn,preferably such that 3D part 22 and support structure 24 extend throughthe opened door assembly 36, controller 54 may stop the operation ofmotor 98, which accordingly stops drawing film 48 in the direction ofarrow 84. Controller 54 may then restart vacuum pump 184 to restrain thesubsequent segment of film 48 to top surface 68. Controller 54 alsopreferably directs platen gantry 174 to raise platform assembly 32 by asmall increment, as illustrated by arrow 192, to disengage retentionbracket 62 from hard stop 180. This allows lateral edges 78 of retentionbracket 62 to press back down against film 48 and top surface 68,thereby again restraining film 48 to top surface 68 (along with thedrawn vacuum).

FIG. 14F illustrates a cutting operation with blade unit 118, where 3Dpart 22 and support structure 24 are depicted by the footprint ofsupport structure 24 for ease of discussion. As shown, controller 54 maythen direct motor 108 to draw blade unit 118 across film 48 along thex-axis in the direction of arrow 120. As discussed above, this cuts film48 at the front end of removal assembly 34, allowing the cut segment offilm 48 with the printed 3D part 22 and support structure 24 to fallinto bucket 58, as shown in FIG. 14G.

As further shown in FIG. 14G, after the cutting step, controller 54 maydirect door assembly 36 to close bi-fold door 46. Controller 54 may alsodirect blade unit 118 to retract back along the x-axis in the directionof arrow 122. At this point, the subsequent segment of film 48 isrestrained by retention bracket 62 and the drawn vacuum. As such, system10 is ready to begin a subsequent printing operation following the samesteps, where platen assembly 32 may be raised back up along the verticalz-axis, as illustrated by arrow 188 and as discussed above.

Accordingly, system 10 is capable of printing and removing multiplesuccessive 3D parts and support structures in an automated manner,preferably without requiring user intervention (other than to changeover consumable assemblies 12). This increases the efficiencies ofprinting operations with system 10, and allows system 10 to operate inan automated printing farm, such as printing farm 10 f (shown in FIG.1).

While system 10 is described above in use with spool supply 50 of film48, platen assembly 32 may alternatively be configured to operate withfilm sheets that are separate from each other, or are perforated forseparation. In these embodiments, the film sheets may be provided in astock or other suitable arrangement for delivery to platen assembly 32.For example, system 10 may include a second assembly similar to removalassembly 34, but located at the rear of platen assembly 32 to deliveringthe film sheets to platen assembly 32.

Furthermore, FIGS. 15-21 illustrate alternative embodiments for platenassembly 32, which utilize different types of substrates for printing 3Dparts. For example, as shown in FIG. 15 platform assembly 32 may be usedwith substrate 192 in lieu of film 48. In this embodiment, platformportion 66 may optionally have a planar top surface 68 withoutindentations 74 or vacuum hole 75, if desired. During use, substrate 192may be placed on top surface 68 (manually or in an automated manner),and retention bracket 62 may be biased down against platform portion 66in the same manner as discussed above for film 48. This securessubstrate 194 between platform portion 66 and retention bracket 62 forreceiving a printed 3D part and support structure.

Substrate 192 is preferably a multi-layer substrate having a porousinterlayer region, and may be fabricated from one or more polymericand/or paper-based materials, and may also include one or moremetallic-film layers (e.g., metal foil layers). For example, substrate192 may be cut from corrugated cardboard to provide a low-costdisposable or recyclable substrate. As further shown in FIG. 15,substrate 192 has top surface 194 for receiving the printed 3D partsand/or support structure, where top surface 194 is perforated with aplurality of holes 196 that extend into the porous interlayer region ofsubstrate 192.

As shown in FIG. 16, when a support structure 24 (or 3D part 22) isprinted on top surface 194, a portion of the printed material flows intoholes 196 in a sprue-like manner, and forms mushroom heads 198 in porousinterlayer region 200 upon cooling. This locks support structure 24 tosubstrate 192, allowing support structure 24 to correspondingly anchor3D part 22 (e.g., for reducing curling effects). Accordingly, substrate192 may be fabricated from low-cost materials that otherwise have lowadhesion to the part or support materials, such as cardboard or otherpaper-based materials.

When the printing operation is completed, substrate 192 may be removedfrom platen assembly 32, and the printed support structure 24 may beremove from holes 196. For example, in embodiments in which substrate192 is fabricated from corrugated cardboard, the pliable nature ofcardboard allows mushroom heads 198 to be pulled out of holes 196 with amoderate amount of pulling force. Alternatively, a cardboard substrate192 may be readily torn apart from support structure 24. The resulting3D part 22 and support structure 24 may then be placed in a supportremoval vessel to remove support structure 24 from 3D part 22. Theexpended substrate 192 may then be discarded, or more preferably,recycled.

In another embodiment, as shown in FIG. 17, top surface 68 of platformportion 66 may be cut away to provide opening 202. Additionally, platenassembly 32 may also include cutting mechanism 203, which is amotor-drive assembly configured to move blade 204 along the y-axis belowopening 202 under direction of controller 54. Cutting mechanism 203 mayfunction in a similar manner to cutting mechanism 90 to move blade 204along the y-axis.

In this embodiment, platen assembly 32 may be used with substrate 206 ina similar manner to substrate 192 (shown in FIGS. 15 and 16). However,substrate 206 is preferably a rigid reusable sheet fabricated from oneor more plastic and/or metallic materials. Substrate 206 may befabricated as one or more layers, but preferably does not include aporous interlayer region. As further shown in FIG. 17, substrate 206 hastop surface 208 for receiving the printed 3D parts and/or supportstructure, where top surface 208 is perforated with a plurality of holes210. However, in comparison to holes 196 of substrate 192, holes 210preferably extend through the entire sheet of substrate 206.

As shown in FIG. 18, when a support structure 24 (or 3D part 22) isprinted on top surface 208, a portion of the printed material flows intoholes 210 in a sprue-like manner, and forms mushroom heads 212 thatextend beyond the bottom surface 214 of substrate 206 upon cooling. Thislocks support structure 24 to substrate 206, allowing support structure24 to correspondingly anchor 3D part 22 (e.g., for reducing curlingeffects). As such, substrate 206 may also be fabricated from low-costmaterials that otherwise have low adhesion to the part or supportmaterials.

When the printing operation is completed, blade 204 may be driven alongthe y-axis in the direction of arrow 216. Blade 202 is desirably flushwith bottom surface 214 of substrate 206 (through opening 202) whensubstrate 206 is secured between platform portion 66 and retentionbracket 62. As such, the movement of blade 202 cuts mushroom heads 212apart from the remainder of support structure 24.

Because mushroom heads 212 no longer lock support structure 24 tosubstrate 206, the printed support structure 24 may be removed fromholes 210 with a low pulling force. The resulting 3D part 22 and supportstructure 24 may then be remove from substrate 206 (and system 10) andthen placed in a support removal vessel to remove support structure 24from 3D part 22. Substrate 206 may then be reused for subsequentprinting operations.

FIGS. 19-21 illustrate alternative embodiments to substrate 192 (shownin FIGS. 15 and 16) and substrate 206 (shown in FIGS. 17 and 18), whichinclude alternative mechanisms for securing the substrates 192 and 206to the platform portions 66. In these embodiments, retention bracket 62may be omitted, if desired. For example, as shown in FIG. 19, platformportion 66 may optionally have a top surface 68 without indentations 74or vacuum hole 75, but may include hook features 218. In someembodiments, top surface 68 may be provided as a separate plate fromplatform portion 66, where the separate plate having top surface 68 maybe securely retained by platform portion 66.

In this embodiment, substrate 192 is further punched or otherwiseperforated with a plurality of hook slots 220 that extend into theporous interlayer region 200 of substrate 192. During use, substrate 194may be placed on top surface 68 (manually or in an automated manner)such that hook features 218 slide into and securely engage hook slots220. This secures substrate 192 to platform portion 66 for receiving aprinted 3D part and support structure.

For example, as shown in FIG. 20, hook slots 220 may extend entirelythrough porous interlayer region 200 of substrate 192. Hook features 218may insert through the bottom surface 222 of substrate 192 and into hookslots 220, such that the tops of hook features 218 reside in porousinterlayer region 200. In some embodiments, hook slots 220 may bepunched into substrate 192 from bottom surface 222, but do not extendthrough top surface 194. However, it is typically easier to manufacturehook slots 220 by punching through the entire body of substrate 192.

As further shown in FIG. 20, when a support structure 24 (or 3D part 22)is printed on top surface 194, a portion of the printed material flowsinto holes 196 in a sprue-like manner, and forms mushroom heads 198 inporous interlayer region 200 upon cooling. This locks support structure24 to substrate 192, allowing support structure 24 to correspondinglyanchor 3D part 22 (e.g., for reducing curling effects). Portions of theprinted layers may also droop into hook slots 220 at top surface 194.However, printing multiple layers of support structure 24 to form ananchor base prior to printing 3D part 22, smoothes out any droops athooks slots 220 and holes 196.

When the printing operation is completed, substrate 192 may be removedfrom platform portion 66, and the printed support structure 24 may beremoved from holes 196, as discussed above. The resulting 3D part 22 andsupport structure 24 may then be placed in a support removal vessel toremove support structure 24 from 3D part 22. The expended substrate 192may then be discarded, or more preferably, recycled.

FIG. 21 illustrates a hook/slot embodiment for substrate 206. As shownin this embodiment, platform portion 66 may include hook slots 224, andsubstrate 206 may include hook features 226. During use, substrate 206may be placed on top surface 68 (manually or in an automated manner)such that hook features 226 slide into and securely engage hook slots224. This secures substrate 206 to platform portion 66 for receiving aprinted 3D part and support structure.

When a support structure (or 3D part) is printed on top surface 208, aportion of the printed material flows into holes 210 in a sprue-likemanner, and forms mushroom heads 212 that extend beyond the bottomsurface 214 of substrate 206 upon cooling. This locks the supportstructure to substrate 206, allowing the support structure tocorrespondingly anchor the 3D part (e.g., for reducing curling effects).When the printing operation is completed, substrate 206 may be removedfrom platform portion 66, and the printed support structure may beremoved from holes 210, as discussed above. The resulting 3D part andsupport structure may then be placed in a support removal vessel toremove the support structure from the 3D part. Substrate 206 may then bereused for subsequent printing operations.

Substrates 192 and 206 (shown in FIGS. 15-21) illustrate examplesubstrates that may be fabricated from low-cost materials, and thatprovide locking mechanisms for anchoring support structures and 3D partsduring printing operations. Holes 196 and 210 provide suitablemechanisms for receiving the printed materials in a sprue-like manner,allowing mushroom heads 198 and 212 to lock the support structures tothe substrates 192 and 206.

Holes 196 and 210 are preferably small enough, and spread apart enoughsuch that they do not negatively impact the printing of supportstructure 24 (or 3D part 22). Examples of suitable average diameters forholes 196 and 210 range from about 0.02 inches to about 0.05 inches.Alternatively, holes 196 and 210 may have non-cylindricalcross-sectionals, where the average cross-sectional areas correspond tothe above-discussed average diameters of holes 196 and 210.

Furthermore, while illustrated in use with platen assembly 32 and system10, substrates 192 and 206 may alternatively be used with a variety ofdifferent platen assemblies and/or additive manufacturing systems. Forexample, substrates 192 and 206 may alternatively be used with otherdeposition-based additive manufacturing systems, such as jetting-basedsystems and other extrusion-based systems.

Although the present disclosure has been described with reference topreferred embodiments, workers skilled in the art will recognize thatchanges may be made in form and detail without departing from the spiritand scope of the disclosure.

The invention claimed is:
 1. An additive manufacturing systemcomprising: a platen gantry; a platen assembly comprising: a platformportion operably retained by the platen gantry, and having a surface; aretention bracket biased towards the platform portion and configured toengage the surface of the platform portion for restraining a filmtherebetween, and to disengage from the surface to release the film; anda wheel; a head gantry configured to retain a print head for printing athree-dimensional part on the restrained film; and a removal assemblycomprising a drive roller, wherein the wheel of the platen assembly andthe drive roller are configured to nip the film therebetween when theplaten assembly engages the removal assembly to draw the released filmhaving the printed three-dimensional part from the platen assembly. 2.The additive manufacturing system of claim 1, wherein the surface of theplatform portion comprises at least one indentation configured to draw avacuum across the surface.
 3. The additive manufacturing system of claim1, and further comprising a support shaft configured to retain a supplyof the film, wherein the support shaft is separate from the platenassembly.
 4. The additive manufacturing system of claim 1, wherein theremoval assembly comprises: a motor; a power screw configured to receiverotatable power from the motor; and a cutting unit threadedly engagedwith the power screw, wherein the cutting unit is configured to cut thedrawn film.
 5. The additive manufacturing system of claim 1, wherein theremoval assembly is separate from the platen assembly and does not movewith the platen assembly.
 6. The additive manufacturing system of claim1, and further comprising: a chamber in which the platen assembly andthe removal assembly are located; and a heating unit configured to heatan environment within the chamber.
 7. The additive manufacturing systemof claim 6, and further comprising: a chamber door the provides accessto the chamber; a motor; and a mechanism operably connecting the chamberdoor and the motor to open and close the chamber door based on anoperation of the motor.
 8. The additive manufacturing system of claim 7,wherein the chamber door comprises a bi-fold door.
 9. An additivemanufacturing system comprising: a platen assembly configured torestrain and release a film, where the platen assembly comprises awheel; a head gantry configured to retain a print head for printing oneor more three-dimensional parts onto the restrained film; a platengantry configured to move the platen assembly along a first axisrelative to the print head while the film is restrained; a removalassembly comprising a drive roller, wherein the wheel of the platenassembly and the drive roller are configured to nip the filmtherebetween when the platen assembly engages the removal assembly todraw the released film having the one or more printed three-dimensionalparts; and a mechanism for retaining a supply of the film, wherein themechanism is not retained by the platen assembly such that movement ofthe platen assembly along the first axis can unwind the film from thesupply.
 10. The additive manufacturing system of claim 9, wherein theplaten assembly comprises: a platform portion having a surfaceconfigured to receive the film; and a retention bracket biased againstthe platform portion to restrain the film against the surface.
 11. Theadditive manufacturing system of claim 10, wherein the platen assemblyfurther comprises retention arms connected to the platform portion, andwherein the retention arms are supported by the platen gantry.
 12. Theadditive manufacturing system of claim 9, wherein the removal assemblycomprises a cutting mechanism that is configured to cut the drawn filmfrom the supply of the film.
 13. The additive manufacturing system ofclaim 9, and further comprising: a chamber in which the platen assemblyand the removal assembly are located; a heating unit configured to heatan environment within the chamber; a chamber door that provides accessto the chamber; a motor; and a second mechanism operably connecting thechamber door and the motor to open and close the chamber door based onan operation of the motor.
 14. The additive manufacturing system ofclaim 9, wherein the additive manufacturing system is a first additivemanufacturing system of a plurality of additive manufacturing systems ina printer farm, wherein each of the plurality of additive manufacturingsystems includes a receiving device configured to receive the filmhaving the printed three-dimensional parts from the additivemanufacturing system.
 15. The additive manufacturing system of claim 9,wherein the platen gantry is configured to move the platen assemblyalong the first axis relative between a raised position and a loweredposition, and wherein the platen assembly engages the removal assemblyat the lowered position.
 16. The additive manufacturing system of claim15, wherein the platen assembly is configured to release the film at thelowered position, and to restrain the film at one or more positionsalong the first axis between the lowered position and the raisedposition.
 17. The additive manufacturing system of claim 9, and furthercomprising a hard stop located along the first axis of movement of theplaten assembly.
 18. The additive manufacturing system of claim 17,wherein the platen assembly comprises a platform portion and a retentionbracket biased against the platform portion to restrain the film againstthe platform portion, and wherein the retention bracket is configured tocontact the hard stop to lift the retention bracket from the platformportion to release the film.